Speaker
Description
Currently, there are different photothermal techniques (PTT) for the characterization of materials that allow obtaining thermal properties from the evolution of temperature over time, based on the generation and detection of thermal waves (TW). The PTT used here is the one proposed for the first time by Nordal and Kanstad in 1979 [1], which they called Photothermal Radiometry (PTR). This technique is based on inducing temperature changes on the sample surface through the incidence of a modulated light beam, producing TW, and detecting the thermal radiation emitted using an infrared sensor. This allows the detection of temperature changes and obtains information that enables the determination of the sample´s thermal properties [2-4]. Studies were realized using the PTR’s back detection configuration on thermal insulating materials. An analytical model was developed and applied to the results of temperature change measurement, in vacuum and ambient temperature under two different modulation frequencies in the intensity of the light beam. Based on the finite element method, numerical simulations of temperature vs time of the PTR process using COMSOL Multiphysics software were obtained [3,4]. The correspondence between the experimental and numerical results demonstrates the usefulness of the developed model for the determination of thermal properties of thermal insulating solids.
Reference
[1] Nordal, Kanstad, (1979). Physica Scripta 659.
[2] Martínez, K et al. (2015). International Journal of Thermal Sciences, 98.
[3] Suarez, V. et al. (2014) Applied Radiation and Isotopes 83.
[4] Wong, J. et al. (2019). Rev. Mex. Fis. 65.
This work was supported by
Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria
| Keywords | Thermal properties; Numerical simulation; Photothermal radiometry |
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